Vassileff, Neiko I. (1440 Midland Ave., Bronxville, NY, 10708)

06/715118

09/16/1986

03/22/1985

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521/83

131/334, 131/332, 521/100, 131/340, 131/335, 106/646, 131/331, 106/680

C04B28/14; C04B28/00; C08G18/14

521/83, 521/100, 131/331, 131/332, 131/334, 131/335, 131/340, 106/86, 106/87, 106/88, 106/109, 106/111

3839059	SPRAYABLE GYPSUM PLASTER COMPOSITION	October, 1974	Rothfelder et al.	106/109
3926650	Foaming agent for plaster and cement compositions	December, 1975	Lange et al.	106/88
3974024	Process for producing board of cement-like material reinforced by glass fiber	August, 1976	Yano et al.	106/88
4084980	Process for preparing a foamed body	April, 1978	Motoki	106/87
4133638	Method of sterilizing powders in a fluidized bed	January, 1979	Healey	422/32
4229223	Gypsum with resin binder	October, 1980	Flake	106/88
4240839	Thermal insulation material	December, 1980	Crepeau et al.	106/88
4265964	Lightweight frothed gypsum structural units	May, 1981	Burkhart	521/83

Welsh, Maurice J.

Lackenbach, Siegel, Marzullo, Presta & Aronson

We claim:

1. A foamed gypsum filter for filtering oxygenated gases comprising carbonaceous material.

2. The filter of claim 1, wherein the oxygenated gases are selected from the group consisting of carbon monoxide, sulfur dioxide, and nitrogen oxides.

3. The filter of claim 1, wherein the carbonaceous material is selected from the group consisting of activated carbon, dried blood, comminuted vegetable matter, chelate and metal chelates.

4. The filter of claim 3, wherein the vegetable matter comprises chlorophyll.

5. The filter of claim 3, wherein the dried blood comprises hemoglobin.

6. The filter of claim 3, wherein the carbonaceous material comprises activated carbon and dried blood.

7. The filter of claim 1, wherein the foamed gypsum and the carbonaceous material are present at about equal weight on a dry basis.

8. The filter of claim 1, wherein the carbonaceous material is present from about one-fifth to about five times the weight of the foamed gypsum.

9. The filter of claim 2, wherein the filter removes from about 58 to about 96% of carbon monoxide flowing through it in a 15-minute period.

10. The filter of claim 2, wherein the filter removes about 18 to about 86% of sulfur dioxide flowing through it in a 15-minute period.

11. The filter of claim 2, wherein the filter removes about 77% of nitrogen oxide flowing through it in a 15-minute period.

12. The filter of claim 3 in the form of a face mask.

13. The filter of claim 3 in the form of a cigarette filter.

14. A filter composition for filtering oxygenated gases selected form the group consisting of carbon monoxide, sulfur dioxide, and nitrogen oxide comprising foamed gypsum, carbonaceous material, and a flexibilizing agent.

15. The filter composition of claim 14, wherein the carbonaceous material is in the form of fine particles selected from the group consisting of activated carbon, dried blood, comminuted vegetable matter, chelate, and metal chelates.

16. The filter composition of claim 14, wherein the flexibilizing agent is sodium polyacrylate.

17. The filter composition of claim 14 further comprising a detergent.

18. The filter composition of claim 14 further comprising a polymeric foam selected from the group consisting of polyurethane, urea-formaldehyde resin, and polystyrene.

19. The filter composition of claim 15, wherein said fine particles are from about -50 mesh to about -300 mesh.

20. The filter composition of claim 15, wherein said carbonaceous material comprises activated carbon and dried blood.

21. The filter composition of claim 15, wherein said carbonaceous material comprises activated carbon and chlorophyll.

22. The filter composition of claim 20 in the form of a face mask filter.

23. A method for making a filter composition for filtering oxygenated gases selected from the group consisting of carbon monoxide, sulfur dioxide, and nitrogen oxide, said composition comprising foamed gypsum, a flexibilizing agent, and a carbonaceous material selected from the group consisting of activated carbon, dried blood, comminuted vegetable matter, chelate and metal chelates comprising:

mixing gypsum, water, and fine particles of the carbonaceous material to form a slurry; and

combining the slurry with a foaming agent.

24. The method of claim 23, wherein the slurry has a a pH from about 7 to about 12.

25. The method of claim 23, wherein the slurry further comprises a detergent.

26. The method of claim 23, wherein the slurry further comprises a foam softening agent.

27. The method of claim 23, wherein the gypsum and carbonaceous material are present in about equal amounts by weight.

28. The method of claim 23, wherein the foaming agent is selected from the group consisting of urethane, urea-formaldehyde resin, styrene, gaseous halocarbon, and polymeric latex.

29. The method of claim 26, wherein said foam softening agent is present in an amount of from about 5 to about 10% by weight of the dry gypsum.

30. The method of claim 23, wherein said fine particles are from about -50 mesh to about -300 mesh.

31. The method of claim 23, wherein said carbonaceous material comprises activated carbon and dried blood.

32. The method of claim 31, wherein the filter removes about 58 to about 96% of carbon monoxide gas initially present at 550 ppm.

33. The method of claim 23, wherein said carbonaceous material comprises activated carbon and chlorophyll.

FIELD OF THE INVENTION

This invention relates to filters. More specifically, this invention relates to a foamed filter composition containing carbonaceous materials.

BACKGROUND AND DISCUSSION OF THE PRIOR ART

In the insulation field it was well known to provide gypsum and foamed gypsum for insulation purposes, such as is disclosed in the following U.S. patents:

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Crepeau et al. 4,240,839 Pratt et al. 3,563,777 Riddell et al. 2,731,377 Dixon et al. 2,862,829 Dickey et al. 2,556,031 Chappell 2,593,008 Mollo 2,602,759 Hoffman 2,913,346 Healey 4,133,638 Yano 3,974,024 Selden 2,915,301 Ergene 3,758,319 Lange et al. 3,926,650 Knowlton 1,798,609 Foster 3,526,685 Bragg et al. 3,719,513 Rothfelder et al. 3,839,059 Upson 1,772,648 Flake 4,229,223 Armstrong 2,664,406 Sucetti 2,921,862 Taylor 2,979,415

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In the filter field, to which the present invention pertains, generally a Hopcolite filter was employed for the removal of carbon monoxide. Hopcolite is a mixture of silver permanganate, copper oxide and nickel oxide. This prior art product was disadvantageous for several reasons, including the fact that it generated heat in use, was relatively expensive and contained substantial heavy metal compounds.

Now there is provided by the present invention a CO filter which is highly effective, non-toxic, non-flammable, light weight, non-settling, does not heat on use, and relatively low cost.

It is therefore a principal object of the present invention to provide a novel filter composition.

It is another object of the present invention to provide a filter composition useful in human user systems such as for example face mask filter and cigarette filter.

It is still a further object of the present invention to provide a filter system as aforesaid which in a broad sense simulates the filter activity of human lungs.

SUMMARY OF THE INVENTION

A filter composition combines a foamed gypsum with fine particulates of a carbonaceous material such as activated carbon, dried blood or comminuted vegetable matter, chelate and metal chelates. The combination of an activated carbon and the dried blood is found to be particularly effective in filter applications.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Broadly speaking, the present invention is a combination of a foamed gypsum with a carbonaceous material dispersed in the foamed gypsum structure. The said combination is proportioned such that to each 100 grams of gypsum there is from 20 to 500 grams of the carbonaceous material. In a more specific aspect the filter composition used to form the filter of the present invention is illustrated in the following TABLE I:

TABLE I

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Component Weight (grams)

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gypsum 100 carbonaceous material 25-125 foam softener or retarding agent 1-10 detergent 2-7

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In forming the foamed gypsum, the composition of Table I is admixed with about 60-70 grams of water to form a slurry. The slurry is then made into a froth or foam by combining with a foaming system or foam generating system. Particularly preferred are foaming systems which employ polymeric foams such as urea-formaldehyde, styrene and the like. These polymeric foaming systems are admixed as a liquid with the slurry. It has been found that the liquid polymeric foaming system may have a pH of approximately 7.0 to 12.0 prior to mixing with the slurry. The polymeric system then cures to a final foam product having a pH less than 7.0. The final pH is due to the prior addition of an acid, such as, for example aluminum sulfate. Other foaming systems are contemplated, including gaseous halocarbon, latex foam, and that foaming system disclosed in U.S. Pat. No. 4,240,839, granted Dec. 23, 1980 to Crepeau et al.

Suitable gypsums useful in the present invention are those well known in the insulation and plaster fields. Such gypsum is found as a natural rock deposit in most parts of the world. In the natural state, gypsum purity ranges from about 80 to 99 percent. Natural gypsum is basically calcium sulfate with two waters of hydration (CaSO ₄ .2H ₂ O). The heating of this gypsum to roughly 400° F. (i.e., so called calcining) will remove all but 1/2 of the two waters of hydration providing a product designated as hemihydrate gypsum (CaSO ₄ .1/2H ₂ O) which is the form that is normally used for making all plaster products. This form is also available as a synthetic byproduct of the fertilizer industry.

It is an important aspect of the present invention to provide carbonaceous material dispersed throughout the foamed gypsum. Preferred carbonaceous material include by way of example, activated carbon, dried blood, metal chelate and comminuted vegetable matter. The dried blood is particularly preferred, and more specifically the combination of dried blood and activated carbon. In the use of the comminuted vegetable matter, those materials containing chlorophyll are most preferred. As stated, a most preferred filter is one which combines activated carbon and dried blood. Other filter specific compounds and combinations are contemplated depending upon the desired end use of the filter. The filter specific compound is generally present in about equal dry weight to the gypsum.

The filter specific compound is preferrably added as fine particulates or powder in the range of -50 to -300 mesh.

Another important aspect of the present invention is the presence of a foam softener or flexibility agent. The agent provides a softer, and perhaps more importantly, less frangible foamed gypsum than that found in the insulation field. A most preferred softening agent is sodium polyacrylate. A non-ionic detergent is also added to the composition to assist in forming the foam. A most preferred detergent is Rohm & Haas X-120 (Rohm & Haas, Philadelphia, PA), which is in a dry, granular form.

The following Examples are illustrative of the invention:

EXAMPLE 1

A slurry was mixed having the following composition:

gypsum (dry): 50 g.

activated carbon: 25 g.

blood ¹ : 25 g.

sodium acrylate: 0.5 g.

non-ionic detergent ² : 5.0 g.

water: 70 g.

1. spray dried

2. Rohm & Haas X-120

The slurry was foamed with air at room temperature for about 10 minutes.

A polymeric foaming system having the following compounds was mixed:

isocyanate: 50 g.

polyol: 50 g.

acid: 5 g.

The foaming system was added to the foamed slurry and allowed to cure to an expanded polyurethane foam. The final product was a dense, relatively soft polyurethane foamed gypsum having a black appearance.

A 1/2-inch thick sample was cut, and an inert gas containing 250 ppm. of CO was passed through the sample for a period of 20 minutes. The outlet gas contained only 14 ppm. CO, indicating a 94% efficiency.

EXAMPLES 2-28

The following general procedure was employed in these Examples 2-28.

Step 1.

One hundred (100) grams of gypsum is mixed with the filter specific compound and an acrylate with 125 gms. water until smooth.

Step 2.

One hundred and fifty (150) ml. of water are mixed with detergent (e.g., Rohm & Haas, Pa.) and an acid (e.g., H ₂ SO ₄ , HNO ₃ , aluminum sulfate) until a foam having the desired consistency is produced.

Step 3.

Mix the products of Steps 1 and 2 into a mold (e.g., bread pan) and place under a sun lamp. After 10-15 minutes transfer bread pan to oven at 192° to 200° F. to evaporate excess water.

The specific compositions for each of the Examples 2-28 are given below in Table II.

TABLE II

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Carbonaceous Material 64.6% Soluble Dried Blood TEST % CO FILTER DURATION CO LEVEL CO LEVEL REDUC- NO. (MINUTES) IN (PPM) OUT (PPM) TION

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2 15 550 240 58 3 15 550 185 66.5 4 15 550 80 85 5 15 550 109 80.5 6 15 550 45 92 carbonaceous material: Gypsum (No Compound) 7 15 527 420 20.9 8 15 527 527 0 9 15 527 340 35.5 carbonaceous material: Hemoglobin and Gypsum 10 120 527 230 56 11 20 527 350 33.6 12 15 527 380 28 13 15 527 340 35.5 14 15 527 340 35.5 carbonaceous material: Dried blood and Gypsum 15 15 527 360 32 16* 15 527 330 37.4 17 15 527 330 75.4 carbonaceous material: Hemoglobin, Activated Carbon and Gypsum 18 15 527 420 75.4 19 15 527 310 40.2 20 80 527 340 35.5 carbonaceous material: Gypsum and Polyurethane 21 15 527 420 10.4 22 15 527 420 10.4 carbonaceous material: Activated Carbon, Polyurethane and Gypsum 23 15 527 380 28 carbonaceous material: Iron chelate and Gypsum 24 15 527 370 29.8 25 15 527 430 18.5 26 15 527 450 14.7 27 15 537 310 41.2 28 15 527 450 14.7

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*Test was with water in filter.

All tests were conducted using a regular flow of about 7.8 mls. per sq. cm. per minute which was adjusted by hand periodically. In addition, material life tests were conducted with the following results:

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FILTER CO LEVEL CO LEVEL % NO. TIME IN OUT REDUCTION

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29 48 hrs. 527 5.0 94

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Further tests were made with an electronic flow meter with the following results:

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MLS. PER CO LEVEL IN CO LEVEL OUT SQ. CM/MIN. FILTER NO. MINUTES (PPM) (PPM) % REDUCTION

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21.7 30 15 510 255 50 7.8 31 15 510 5.0 96

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EXAMPLES 2-3

Step 1.

100 grams gypsum

25 grams activated carbon

50 grams 64.6% solution dry blood

1 gram polyacrylate

Above dissolved in 125 grams water. Stir until smooth, no lumps.

Step 2.

150 cc. water

8 cc. Triton X-100

15 gr. acid

EXAMPLE 4

Step 1.

100 gr. gypsum

25 gr. activated carbon

50 gr. 64.6% soluble dry blood

1 gr. polyacrylate

25 gr. Elmer's glue

Step 2.

150 gr. water

8 cc. Triton X-100

EXAMPLE 5

Step 1.

100 gr. gypsum

25 gr. activated carbon

50 gr. 64.6% soluble dry blood

1 gr. polyacrylate

50 gr. Elmer's glue

Step 2.

150 gr. water

8 cc. Triton X-100

15 gr. acid

EXAMPLE 6

Step 1.

100 gr. gypsum

25 gr. activated carbon

50 gr. 64.6% soluble dry blood

1 gr. polyacrylate

25 gr. Elmer's rubber cement

Step 2.

150 gr. water

8 cc. Triton X-100

15 gr. acid

EXAMPLE 7

Step 1.

100 gr. gypsum

50 gr. isocyanide

1 gr. sodium acrylate

8 gr. Triton X-100

80 gr. H ₂ O

Step 2.

100 gr. H ₂ O

50 gr. polyol

8 gr. Triton X-100

20 gr. acid

EXAMPLE 8

Step 1.

100 gr. gypsum

1 gr. sodium polyacrylate

100 cc. H ₂ O

EXAMPLE 9

Step 1.

100 gr. gypsum

1 gr. sodium acrylate

70 cc. H ₂ O

Step 2.

80 cc. H ₂ O

8 gr. Triton X-100

35 gr. B Rabbit BS Molasses

20 gr. acid

EXAMPLE 10

Step 1.

100 gr. gypsum

95 gr. hemoglobin

1 gr. polyacrylate

150H ₂ O

Step 2.

140 gr. H ₂ O

8 gr. Triton X-100

35 gr. Molasses

20 gr. acid

EXAMPLE 11

Step 1.

100 gr. gypsum

50 gr. hemoglobin

1 gr. polyacrylate

100 gr. H ₂ O

Step 2.

100 gr. H ₂ O

8 gr. Triton X-100

20 gr. acid

EXAMPLE 12

Step 1.

100 gr. gypsum

50 gr. hemoglobin

1 gr. polyacrylate

140 gr. H ₂ O

50 gr. isocyanide

Step 2.

100 gr. H ₂ O

8 gr. Triton X-100

25 gr. acid

50 gr. polyol

EXAMPLE 13

Step 1.

100 gr. gypsum

100 gr. hemoglobin

1 gr. sodium acrylate

150 gr. H ₂ O

Step 2.

140 gr. H ₂ O

8 gr. Triton X-100

35 Molasses

20 gr. acid

EXAMPLE 14

Step 1.

100 gr. gypsum

125 gr. hemoglobin

1 gr. sodium acrylate

200 gr. H ₂ O

Step 2.

150 gr. H ₂ O

8 gr. Triton X-100

30 gr. Molasses

25 gr. acid

EXAMPLE 15-16

Step 1.

100 gr. gypsum

125 gr. dried blood

1 gr. sodium acrylate

200 gr. H ₂ O

Step 2.

150 gr. H ₂ O

8 gr. Triton X-100

30 gr. Molasses

25 gr. acid

EXAMPLE 17

Step 1.

100 gr. gypsum

125 gr. dried blood

1 gr. sodium acrylate

250 gr. H ₂ O

30 gr. activated carbon

Step 2.

150 gr. H ₂ O

8 gr. Triton X-100

30 gr. Molasses

25 gr. acid

EXAMPLE 18

Step 1.

100 gr. gypsum

50 gr. hemoglobin

*35 gr. Flambinder NX

25 gr. activated carbon

120 gr. H ₂ O

Step 2.

140 gr. H ₂ O

8 gr. Triton X-100

10 gr. acid

EXAMPLE 19

Step 1.

100 gr. gypsum

50 gr. hemoglobin

*35 gr. Flambinder NX

25 gr. activated carbon

120 gr. H ₂ O

Step 2.

140 gr. H ₂ O

8 gr. Triton X-100

20 gr. acid

EXAMPLE 20

Step 1.

100 gr. gypsum

50 gr. hemoglobin

1 gr. polyacrylate

100 gr. H ₂ O

50 gr. isocyanide

*25 gr. Flambinder

Step 2.

100 gr. H ₂ O

8 gr. Triton X-100

25 gr. acid

50 gr. polyol FNT *Flambeau Paper Corporation Park Falls, Wis. (U.S.A.)

EXAMPLE 21

Step 1.

100 gr. gypsum

50 gr. isocyanide

80 gr. H ₂ O

1 gr. sodium acrylate

Step 2.

100 gr. H ₂ O

50 gr. polyol

8 gr. Triton X-100

10 gr. acid

EXAMPLE 22

Step 1.

100 gr. gypsum

50 gr. polyol

1 gr. sodium acrylate

20 gr. H ₂ O

Step 2.

100 gr. H ₂ O

50 gr. isocyanide

8 gr. Triton X-100

10 gr. acid

EXAMPLE 23

Step 1.

100 gr. gypsum

25 gr. activated carbon

50 gr. isocyanide

1 gr. sodium acrylate

100 gr. H ₂ O

Step 2.

100 gr. H ₂ O

50 gr. polyol

10 gr. acid

8 gr. Triton X-100

EXAMPLE 24

Step 1.

100 gr. gypsum

50 gr. isocyanide

1 gr. sodium acrylate

50 gr. H ₂ O

8 gr. Triton X-100

Step 2.

50 gr. iron chelate

100 gr. H ₂ O

50 gr. polyol

10 gr. acid

8 gr. Triton X-100

EXAMPLE 25

Step 1.

100 gr. gypsum

50 gr. isocyanide

1 gr. sodium acrylate

50 gr. H ₂ O

8 gr. Triton X-100

25 gr. activated carbon

Step 2.

50 gr. Iron chelate

100 gr. H ₂ O

50 gr. polyol

10 gr. acid

8 gr. Triton X-100

EXAMPLE 26

Step 1.

100 gr. H ₂ O

100 gr. gypsum

50 gr. isocyanide

1 gr. sodium acrylate

8 gr. Triton X-100

25 gr. activated carbon

Step 2.

100 gr. H ₂ O

50 gr. polyol

50 gr. iron chelate

20 gr. acid

8 gr. Triton X-100

EXAMPLE 27

Step 1.

100 gr. gypsum

50 gr. isocyanide

50 gr. iron chelate

1 gr. sodium acrylate

100 gr. H ₂ O

8 gr. Triton X-100

25 gr. activated carbon

Step 2.

100 gr. H ₂ O

50 gr. polyol

20 gr. acid

8 gr. Triton X-100

EXAMPLE 28

Step 1.

100 gr. gypsum

50 gr. isocyanide

1 gr. sodium acrylate

8 gr. Triton X-100

60 gr. H ₂ O

Step 2.

100 gr. H ₂ O

50 gr. polyol

20 gr. acid

8 gr. Triton X-100

50 gr. iron chelate

In yet a further example of the invention, the following composition of the filter was made with chlorophyll in lieu of dried blood and activated carbon.

Step 1.

100 gr. gypsum

25 gr. chlorophyll

1 gr. sodium acrylate

120 gr. H ₂ O

Step 2.

100 gr. H ₂ O

10 gr. Triton X-100

15 gr. Al-sulfate

Step 3.

75 gr. polyol

75 gr. isocyanide

In this further example noted hereinabove, the test results obtained were as follows:

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Filter of further example

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SO 2 SO 2 % Flow Time Level In Level Out Reduction

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Example 4 7.8 15 min. 515 412 18% filter 7.8 15 min. 515 72 86%

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NO x NO x % Level In Level Out Reduction

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Example 4 7.8 15 min. 520 100 77% filter

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The SO ₂ and NO _x gases were obtained from commercial sources wherein the SO ₂ was contained in a pressurized air tank having 515 ppm; and the NO _x was likewise provided in a pressurized air tank and exhibited 520 ppm which consisted of 80% NO and 20% NO ₂ . The filter samples of Examples 2-28 were tested by passing an essentially inert gas containing measured parts per million of CO from a compressed gas tank, through each sample. All tests were conduted at a gas flow of 7.8 ml/sq.cm. The level of CO at the downstream side of the filter was measured, and the percent CO reduction calculated. The test results are shown above in Table II.

It has been demonstrated that the combination of a carbonaceous material in a foamed gypsum reduces the CO. The combination of dried blood and activated carbon in a foamed gypsum is a particularly effective filter, in removing 58 to 96% of the CO over a 15 minute period.

The filter composition of the present invention may be used as air or smoke filters (e.g., smoke masks, cigarette filters, air conditioner filters, air purifiers, furnace filters, and the like); oil filters (e.g., automobiles, trucks, stationary engines), and water/aqueous liquid filters (e.g., general filtration, sewerage treatment, swimming pools, beer and wine production, and general solvent filtration). The filter product of the present invention is useful in many applications, including by way of examples, filter aids, filter bags, filter cloth, filter elements, filter materials, filter systems, air filters, filter activated carbon, air compressorfilters, enginefilters, automotive filters, mechanical filters, cartridges, chemical filters, coalescing filters, compressor filters, coolant, electronic, food product, gas, hydraulic, industrial, instrument, microwave, military, pressure, gravity, refrigeration, taste and odor removal and other filter equipment.

It is important to note that gypsum, unlike asbestos filter material, is non-toxic and non-carcinogenic and therefore is highly useful in human breathing filter applications. In addition, gypsum does not burn under the heat present in fires and normal burning situations and therefore the human breathing filter applications are complemented in this regard. Particularly preferred human use applications are cigarette and smoke mask filters. Where human breathing applications are contemplated, the foaming system employed should also be one which will withstand the high temperatures contemplated.

Without wishing to be bound by any theory or mechanism, it is believed that the activated carbon/dried blood foamed gypsum filter, as well as the foamed gypsum/chlorophyl filter (without dried blood or activated carbon) in a broad sense, simulates the gas and particulate filter aspects of the human lung. Thus, for example, a cigarette filter embodying the invention will remove those noxious gases and particulates normally entrained by the lung tissues.

Also, it will be appreciated that the filters of the present invention form a solid, dry, hard porous material which can be used to remove not only CO, but also SO ₂ and NO _x and other like gaseous contaminating or noxious compounds.

In yet further testing of filters made in accordance with the present invention, the following test data was obtained on runs made on the filters:

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Filter Test CO Level In CO Level Out No. (Hours) (PPM) (PPM) % Reduction

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32 1.0 527 115 78 33 1.75 527 103 80.5 34 4.0 527 90 82.9 35 5.0 527 110 79.1 36 5.5 527 160 69.5

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Although the invention has been described with respect to certain specific embodiments, it will be appreciated that modifications and changes may be made by those skilled in the art within the true spirit and scope of the invention.